This week, a very rare glimpse of the whale shark - the world's largest fish - the history of the edible dormouse, a brace of barn owls in Cheshire, and, under the microscope, the miniature world of the eyelash mite.
With Michaela Strachan, Howie Watkins, Janice Acquah, and Nick Baker.
(Repeated tomorrow at 8.05am on BBC2)